1. Technical Field
The present invention generally is related to the field of bicycles and bicycle frames with rear suspensions, and more particularly to downhill and dirt jump bicycles.
2. Related Art
Many conventional bicycles include front and rear suspension systems to increase the shock absorption capability of the bicycle and to increase the comfort and safety of the rider. Some of these conventional rear suspensions systems, however, are manufactured in a way that leave the frame with inadequate strength to handle the impact of downhill and dirt jumping cycling. These inadequate frames can lead to catastrophic failure of the bicycle in some instances and can cause severe injury to a rider. To combat such frame failures, many rear suspension system designs known in the art increase the strength of the frames through either using more materials in the frame, or use stronger and therefore heavier materials. Increasing the weight and mass of the frame affects the speed, handling, and aerodynamics of the bicycle. Therefore, improvements to suspension system components can increase the strength and performance of the bicycle without reducing the speed, handling, or aerodynamics of the frame.
The suspension systems typically incorporated in the rear of a bicycle, particularly in a downhill and cross-country bicycle, suffer from problems involving the bicycle chain. A bicycle's chain length, i.e., the distance between the chain ring/bottom bracket and the rear cogs/hub, can change as the bicycle's suspension system is activated. For example, a sudden increase in a chain's length can cause the chain to disengage from the chain ring or gears, causing the rider a complete loss of pedaling ability. Additionally, conventional bicycle rear suspension systems can encounter problems when a rider's pedaling action interferes with suspension movement. Likewise, suspension movement can interfere with a rider's pedaling in some rear suspension system designs. Further, many suspension systems are difficult to adjust.
Accordingly, there is a need for a bicycle suspension system and frame design that has adequate shock absorbing capability without hindering the speed, handling, or aerodynamics of the bicycle. There is also a need for a bicycle suspension system and frame design that does not affect and is not affected by the chain's length or the pedaling action of the bicycle. There is also a need for a bicycle suspension system and frame that is easily adjustable and repairable. Finally, there is a need for a bicycle suspension system and frame design that is strong and safe for a rider. The present invention is directed toward solving the above identified problems.